Modal window for a computer display screen



FIG. 1 is a front view of a modal window for a computer display screen;

FIG. 2 is a front view of a second embodiment thereof; and,

FIG. 3 is a front view of a third embodiment thereof.

The broken line drawing of a window border in FIG. 3 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a modal window for a computer display screen, as shown and described. 